THE SWAY PATHS OF THE CENTER OF GRAVITY OF HEMIPARETIC PATIENTS IN THE SITTING POSITION
Nobuyuki Kawate, Masazumi Mizuma, Yoshiaki Mori (Showa University, Tokyo, Japan)
Abstract: To evaluate the sitting balance of hemiparetic stroke patients, we analyzed the sway paths of the center of gravity in the sitting position with a gravicorder. Subjects were 51 patients (16 women and 35 men) whose mean age was 60.7±9.4 years, and 46 healthy subjects (27 women and 19 men) of the control group whose mean age was 58.3±20.6 years. For the static sitting position, we instructed subjects to sit on a chair on a gravicorder. Maximal anterior-posterior distance (max-AP) and maxmal right-left distance (max-RL) of the sway paths of the center of gravity were measured for 50 seconds. For the shifting sitting position, we instructed subjects to perform voluntary anterior and lateral flexion; these movements were repeated every 2 seconds, and max-AP in anterior flexion and max-RL in lateral flexion were measured for 40 seconds. Max-AP and max-RL of the control group were significantly less than that of patients (p<0.01). Max-AP in anterior flexion and max-RL in lateral flexion of the control group were significantly greater than that of patients (p<0.01). In patients, max-AP and max-RL tended to be less, and max-AP in anterior flexion and max-RL in lateral flexion tended to be greater owing to better standing ability and ambulatory activity. We concluded that with measurements of the sway paths of the center of gravity in the sitting position, patients can be examined on the basis of the control of sitting balance.
RELATION BETWEEN SOME ANATOMICAL MARKERS AND POSITION OF THE CENTER OF GRAVITY 1N STANDING POSTURE OF HEALTHY SUBJECTS
Kawai N., Yoshida Y., Mizukami M., Koyama N., Nakamura R. (National Rehabilitation Center for the Disabled, Tokorozawa, Japan) Measurement of the position of center of gravity (COG) in standing posture is clinically important to assess the stability of balance of patients. First, we examined position of COG relative to the base of support in 20 healthy subjects aged from 15 to 60 years, using Gravicorder-G5500 (Anima). The position of COG was measured every 10 msec for 10 sec, while the subjects stood still on the platform. The results showed that position of COG located 39.6 percentile of the base of support from the posterior edge in the sagittal plane. Secondly, we examined the relation of COG to anatomical landmarks in the lateral view, i.e., the auricular lobule, the acromion, the greater trochanter, the knee (anterior 1/3 of a-p. diameter), and the lateral malleolus in 14 healthy male subjects aged from 18 to 32 years, using video and analog motion measurement systems (PEAK). The line of COG coincided with the acromion and the greater trochanter, and located near the knee marker, 5.6 cm anterior of the lateral malleolus, 2.2 cm posterior of the auricular lobule.